Ring node and redundancy method

Abstract

To provide a technology capable of improving fault-tolerance by redundancy-structuring each of ring nodes building up a ring network with an active termination block and a non-active termination block and, if a fault occurs in the active termination block, continuing an operation by switchover to the non-active termination block. A ring node is configured such that data from a terminal side is forwarded to an active termination block and to a non-active termination block, source information of the data is determined and registered in a database, the data is transmitted to the ring from a ring-side interface, the data received from the ring is forwarded to the active termination block and to the non-active termination block, destination information of the data is determined by referring to the database and forwarded to a terminal-side interface, and the terminal-side interface selects the data from the active termination block and forwards the selected data to the terminal side.

1 . A ring node building up a ring network, comprising:
 a ring-side interface receiving data from the ring or transmitting the data to the ring;   an active termination block forwarding the data from the ring to a terminal side or forwarding the data from the terminal side to the ring;   a non-active termination block redundancy-structuring a forwarding function of the data by having the same configuration as the active termination block has; and   a terminal-side interface selecting the data sent from the active termination block in the data from the active termination block and from the non-active termination block, then forwarding the selected data to the terminal side, and forwarding the data from the terminal side to the active termination block and to the non-active termination block,   each of the active termination block and the non-active termination block including:   a source determining unit determining source information of the data received from the terminal side, and registering the source information in a database; and   a destination determining unit determining destination information of the data received from the ring by referring to the database.   
   
   
       2 . The ring node according to  claim 1 , wherein the ring-side interface forwards the data received from the ring to the active termination block and to the non-active termination block, then selects the data from the active termination block in the data from the active termination block and from the non-active termination block, and forwards the selected data to the ring side, and
 each of the active termination block and the non-active termination block includes:   the source determining unit and the destination determining unit;   a source determining unit determining the source information of the data received from the ring side, and registering the source information in a database; and   a destination determining unit determining a forwarding destination of the data by referring to the database on the basis of the destination information of the data received from the terminal side.   
   
   
       3 . The ring node according to  claim 1 , wherein the non-active termination block, after registering the source information of the data in the database, discards the data. 
   
   
       4 . The ring node according to  claim 2 , wherein each of the active termination block and the non-active termination block includes a terminal-side block and a ring-side block,
 the terminal-side block includes: the source determining unit determining the source information of the data received from the terminal side, and registering the source information in the database; and the destination determining unit determining the destination information of the data received from the ring by referring to the database,   the ring-side block includes: a source determining unit determining the source information of the data from the ring side, and registering the source information in the database; and a destination determining unit determining the forwarding destination of the data by referring to the database on the basis of the destination information of the data received from the terminal side, and   the terminal-side block and/or the ring-side block of the non-active termination block, after registering the source information of the data in the database, discards the data.   
   
   
       5 . The ring node according to  claim 1 , wherein the ring-side interface forwards the whole data received from the ring to the active termination block, and forwards a part, related to the source information, of the data received from the ring to the non-active termination block. 
   
   
       6 . The ring node according to  claim 1 , wherein the terminal-side interface forwards the whole data received from the terminal side to the active termination block, and forwards a part, related to the source information, of the data received from the terminal side to the non-active termination block. 
   
   
       7 . The ring node according to  claim 1 , wherein each of the active termination block and the non-active termination block includes:
 a database transfer unit transferring, when detecting a changeover to another termination block, the information in the database to the changed another termination block; and   a database initial registering unit registering, when receiving the information from the database transfer unit in the database, the information in a database.   
   
   
       8 . The ring node according to  claim 7 , wherein the database transfer unit transfers the information in the database to the terminal-side interface via a transfer route of the data, and
 the terminal-side interface transfers the information in the database to the database initial registering unit via the transfer route of the data.   
   
   
       9 . The ring node according to  claim 7 , wherein the database transfer unit transfers the information to the database initial registering unit via a communication route of control information. 
   
   
       10 . The ring node according to  claim 7 , wherein the database transfer unit transfers the information to the database initial registering unit via a dedicated communication route. 
   
   
       11 . A redundancy method for a ring node including a ring-side interface, an active termination block, a non-active termination block and a terminal-side interface, the method, executed by the ring node, comprising steps of:
 getting the terminal-side interface to forward data from a terminal side to the active termination block and to the non-active termination block;   getting the active termination block and the non-active termination block to determine source information of the data received from the terminal side and to register the source information in a database;   getting the active termination block to forward the data to the ring-side interface;   getting the ring-side interface to send the data to the ring;   getting the ring-side interface to receive the data from the ring and to forward the data to the active termination block and to the non-active termination block;   getting the active termination block to determine destination information of the data received from the ring-side interface by referring to the database, and to forward the data to the terminal-side interface; and   getting the terminal-side interface to select the data from the active termination block in the data from the active termination block and from the non-active termination block, and to forward the selected data to the terminal side.   
   
   
       12 . The redundancy method according to  claim 11 , further comprising steps of, as those executed by the ring node:
 getting the ring-side interface to forward the data received from the ring to the active termination block and to the non-active termination block;   getting the active termination block and the non-active termination block to determine the source information of the data received from the ring side, and to register the source information in a database;   getting the active termination block to determine destination information of the data received from the terminal-side interface by referring to the database, and to forward the data to the ring-side interface; and   getting the ring-side interface to select the data from the active termination block in the data from the active termination block and from the non-active termination block, and to forward the selected data to the ring.   
   
   
       13 . The redundancy method according to  claim 11 , wherein the non-active termination block, after registering the source information of the data in the database, discards the data. 
   
   
       14 . The redundancy method according to  claim 12 , wherein each of the active termination block and the non-active termination block includes a terminal-side block and a ring-side block,
 the terminal-side block executes steps of: determining the source information of the data received from the terminal side and registering the source information in the database; and determining the destination information of the data received from the ring by referring to the database,   the ring-side block executes steps of: determining the source information of the data received from the ring side and registering the source information in the database; and determining a forwarding destination of the data on the basis of the destination information of the data received from the terminal side by referring to the database, and   the terminal-side block and/or the ring-side block of the non-active termination block, after registering the source information of the data in the database, discards the data.   
   
   
       15 . The redundancy method according to  claim 11 , wherein the ring-side interface forwards the whole data received from the ring to the active termination block, and forwards a part, related to the source information, of the data received from the ring to the non-active termination block. 
   
   
       16 . The redundancy method according to  claim 11 , wherein the terminal-side interface forwards the whole data received from the terminal side to the active termination block, and forwards a part, related to the source information, of the data received from the terminal side to the non-active termination block. 
   
   
       17 . The redundancy method according to  claim 11 , wherein each of the active termination block and the non-active termination block transfers, when detecting a changeover to another termination block, the information in the database to the changed another termination block; and registers, when receiving the information in the database, the information from the database transfer unit in a database. 
   
   
       18 . The redundancy method according to  claim 17 , wherein the information in the database is forwarded to the terminal-side interface via a forwarding route of the data, and
 the terminal-side interface forwards the information in the database to another termination block via the forwarding route of the data.   
   
   
       19 . The redundancy method according to  claim 17 , wherein the information in the database is forwarded via a communication route of control information of each of the active termination block and the non-active termination block. 
   
   
       20 . The redundancy method according to  claim 17 , wherein the information in the database is forwarded via a dedicated communication route.